ROD CARTRIDGE FOR A ROCK DRILLING EQUIPMENT

Abstract: A rod cartridge for a rock drilling equipment, rotatable about a shaft (10) and comprising a rotor having guide plates (15a to 15c), and end covers (11, 13). One end cover (13) of the rod cartridge (1) is displaceable longitudinally of the shaft (10). The guide plate (15c) close to the displaceable end cover (13) is similarly displaceable longitudinally of the shaft (10) so that the rod cartridge (1) can be adjusted for rods of different lengths.

Description: Rod cartridge for a rock drilling equipment The invention relates to a rod cartridge for a rock drilling equipment, the rod cartridge comprising a rotor with guide plates for rods; end covers having end surfaces, the rods being placeable between the end covers; and rotation means mounted in one end cover for rotating the rotor. Rod cartridges are used in rock drilling equip- ment for storing drill rods or drill pipes used in long-hole drilling and bolts used in rock bolting. As used in this patent application and claims, the rod refers to drill rods and drill pipes used in long-hole drilling or to bolts used in rock bolting. The rock drilling equipment in turn refers in this patent application and claims both to a rock drilling equip¬ ment and to a bolting equipment used in rock bolting. Cartridge solutions known from the prior art typically utilize different kinds of rotating cart- ridges comprising end plates and usually two or three guide plates between the end plates. A rod is posi¬ tioned between the end plates into slots formed in the guide plates. By rotating the guide plates by a mechanism based on the so-called Maltese cross prin- ciple, the slots can be turned successively in align¬ ment with a cartridge feed opening or to a feeding position for placing rods into the cartridge and removing them from the cartridge. This type of cart¬ ridge is well-known and of a structure self-evident to one skilled in the art, so it will not be described more fully herein. A problem with the prior art cartridge solutions is that the cartridges are of such dimensions that they can accommodate only rods of a predetermined length. If such a cartridge is used for rods of a different length, it is necessary to change fixed cartridge structures in order that the cartridge would operate in a desired way. This is problematic especially when the rods are rock bolts having widely varying manufacturing tolerances. If the cartridge is designed for a certain rod length, rods of a greater length cannot be stored in it, and even a few tens of millimetres may render a rod lot unsuitable for the cartridge. Similarly, if it is necessary to use re- inforcing bolts and extension rods of different lengths e.g. in underground excavations and due to rock structures, a single equipment provided with the prior art cartridges cannot be used with the different lengths, as the components that should be changed to modify the equipment are too large. As a result, it is necessary to use two different equipment, which often causes extra costs. A further problem with the prior art solutions is that a change in the rod length requires changes in the mounting of the rod gripping arms with respect to the equipment, which involves extra work. The object of the present invention is to provide a rod cartridge which can be used for storing rods of different lengths according to the require- ments and which is easily and rapidly adjustable for different rod lengths. The rod cartridge according to the invention is characterized in that one of the end surfaces is displaceable in the longitudinal direction of the rotor so that the distance of the end surface from the opposite end surface is adjustable according to the length of the rod to be used. An essential feature of the invention is that the end surface at one end of the rod cartridge and the guide plate close to it are displaceable in the longitudinal direction of the rod cartridge such that the distance between the end covers can be adjusted for the length of a rod to be used, and the guide plates can be positioned at suitable distances to facilitate the handling of the rod. An essential feature of a preferred embodiment of the invention is that one of the gripping/displacing arms needed for rod handling is similarly displaceable so that rods of different lengths can be gripped at an optimal point with respect to the guide plates. According to the preferred embodiment of the invention, the displace¬ able end surface of the cartridge is mounted at the end close to the rock drill and the bolt feeding device, respectively. This ensures that the opposite end of the rod will always be positioned at the guide of the feeding beam or at a drill hole to be bolted so that any aligning problems are avoided. Further according to the preferred embodiment of the inven¬ tion, the cartridge rotation machinery and rotation motor are mounted in close proximity to the displace- able end cover, so that the dimensions of the cart¬ ridge will be as small as possible at the front end of the feeding beam of the rock drill and the rod will be fed in a desired way in alignment with either the drilling axis of the rock drill or the feeding axis of the bolting head. An advantage of the solution according to the invention is that the transition from one rod length to another takes places rapidly and simply merely by displacing the end cover and the guide plate to a desired position. Similarly, if the rod length varies from a predetermined value, the cartridge may also be adjusted to the wrong rod length without any laborious and expensive replacement of the parts. Moreover, the cartridge according to the invention allows a suitable bolt length to be used at the same working site according to the requirements, which involves savings in material costs. The invention will be described more fully with reference to the attached drawings, in which Figure 1 is a schematic top view of a rock bolt¬ ing equipment; Figure 2 shows the rock bolting equipment of Figure 1 in a direction A indicated in Figure 1; Figures 3a and 3b show a rod cartridge according to the invention in two positions adjusted for dif¬ ferent rod lengths; Figure 4 is a schematic view of a gripping arm as seen in the direction of the turning axis; Figure 5 is a schematic side view of another embodiment of the invention. Figure 1 is a schematic top view of a rock bolting equipment. The equipment comprises one embodi¬ ment of the rod cartridge according to the invention, i.e. a bolt cartridge 1. It further comprises a bolt- ing head 2 movable along its own feeding beam 2a, and a rock drill 3 similarly movable along its own feeding beam 3a. It also comprises gripping arms 4 connected to a mounting beam 5 turnably about a shaft 6. The bolting head 2 and the rock drill 3 and the gripping arms 4 with their beams are connected as a single unit to a base 7 turnable about a vertical shaft 8. Both the base 7 and the cartridge 1 are connected to an equipment frame 9. Figure 2 shows the rock bolting equipment of Figure 1 as seen in a direction A indicated in Figure 1. It appears from Figure 2 that there are two gripping arms 4 spaced mutually so that rods (not shown in Figure 2) placed in the cartridge 1 can be gripped and withdrawn from the cartridge into align- ment with a hole to be bolted. In Figure 2, the parts corresponding to those shown in Figure 1 are indicated with the same reference numerals with the exception of the gripping arms, which are indicated with the refer¬ ence numerals 4a and 4b for the sake of clarity. Figures 3a and 3b show a rod cartridge according to the invention adjusted for a short rod and a long rod, respectively. The rod cartridge is formed of a central tube or shaft 10 mounted for rotation with respect to an upper fixed end cover 11. A tubular support arm 12 formed of an outer tube 12a and an inner tube 12b disposed longitudinally movably within the outer tube is also attached to the upper end cover 11. The inner tube 12b can be secured immovable with respect to the outer tube 12a by a squeezer 12c. The inner tube 12b in turn is attached to another end cover 13 within which means for rotating the cart¬ ridge, i.e. a Maltese cross mechanism, is disposed and to which a rotation motor 14 is also connected. The other end cover 13 is positioned around the shaft 10, and it can be displaced longitudinally of the shaft. Guide plates 15a to 15c are also attached to the shaft 10. The guide plates are provided with slots into which rods 16 are placed in a manner known per se. The guide plates 15a to 15c are further provided with retainer springs 17a to 17c which keep the rods 16 in position in the slots. The rotation mechanism within the other end cover 13 is attached to the shaft 10 unrotatably by means of a friction connecting sleeve 18. Similarly, the guide plate 15c closest to the end cover 13, i.e. the bottommost guide plate in the figure, is attached to the shaft 10 by a similar friction connecting sleeve 19. To adjust the length of the cartridge for a rod to be used, the squeezer 12c and the friction connect- ing sleeves 18 and 19 are opened. The lower end cover is thereafter displaced as shown in Figure 3a such that the rod 16 will be positioned between the end surfaces 11a and 13a of the end covers 11 and 13. The friction connecting sleeve 18 and 19, respectively, is then tightened so that the Maltese cross mechanism within the end cover 13 is connected unrotatably to the shaft 10, and the guide plate 15c is similarly connected unrotatably to the shaft 10. The guide plates 15a and 15b are preferably mounted fixedly to the shaft 10, as they need not be displaced when the length of the rod 16 varies. Figure 3b in turn shows a situation in which the cartridge has been adjusted for a long rod 16'. In this case, the squeezer 12c of the tubes 12a and 12b has correspondingly been opened first and then the friction connecting sleeves 18 and 19, whereafter it has been possible to displace the other end cover 13 and its motor and the guide plate 15c to the bottom end of the shaft 10. The friction connecting sleeves 18 and 19 and the squeezer 12c between the tubes 12a and 12b have thereafter been tightened. In the cases of both of the figures, the rotation of the motor 14 rotates the Maltese cross, which rotates the shaft 10 via the friction connecting sleeve 18. The guide plates 15a to 15c thus also rotate, displacing the rod 16 or 16' to a position for withdrawing the rod from the cartridge; alternatively, in the case of long-hole drilling, for placing a detached extension rod into an empty slot in the guide plates 15a to 15c. Figures 3a and 3b further show how the lower gripping arm 4b has been displaced similarly as the cartridge end cover 13 so that it is at a suit¬ able distance from the ends of the rod 16. Both of the gripping arms 4a and 4b are connected to the shaft 6 (not shown in the figure) passing through them. The shaft 6 is hexagonal in cross-section, but it is mounted turnably to a stand 20 shown in Figure 4. The stand 20 comprises a slot 21 for an I-shaped beam 5. The stands 20 are attached to the beam 5 by mounting bolts 22 so as to fix the arm with respect to the beam 5. The arms 4 are turned by turning the shaft 6 by a power unit known per se (not shown), such as a hydraulic motor or cylinder. To displace the gripping arms 4, or the gripping arms 4a and 4b shown in Figures 3a and 3b, the mount- ing bolts 22 are opened so that the stand 20 is slid- able along the track 5. As the gripping arms are con¬ nected to the shaft 6 shown in the figure by a hexa¬ gonal hole whereas they are not fixed to the shaft in any way, they are also able to slide with respect to the shaft 7, being thus easily and simply adjustable to a desired position. When the gripping arm is in a desired position, the mounting bolts 22 of the stand 20 are tightened so that the gripping arm will not move with respect to the stand. Figure 5 shows another embodiment of the inven¬ tion in which the cartridge itself is fixed in length, that is, the end covers 11 and 13 are interconnected by an integral supporting arm 12. In this embodiment, the end surfaces 11a and 13a form part of separate end plates lib and 13b connected for rotation with the rotor shaft 10 so that the rods 16 contained in the cartridge will not chafe the end surfaces 11a and 13a. In this embodiment the end plate 13b is displaceable in the longitudinal direction of the shaft 10 so as to adjust the distance between the end surfaces 13a and 11a in accordance with the length of the rod 16. Cor¬ respondingly, the guide plate 15c close to the dis¬ placeable end plate 13b is displaceable in the longit¬ udinal direction of the shaft 10. The end plate 13b and the guide plate 15c may both be arranged to be separately attached unrotatably to the shaft either by a friction connecting sleeve mentioned above or other fixing means. Similarly, the guide plate 15c and the end plate 13b may be fixed to each other, in which case a single fixing means will suffice, such as a friction connecting sleeve. In this embodiment, the Maltese cross mechanism operated by the rotation motor may be connected fixedly to rotate the shaft 10. The invention has been described in the above text and shown in the drawings only by way of example and the solution is . not in any way limited to the examples. The rotation mechanism and the guide plate 15c may be connected to the shaft 10 unrotatably in dif- ferent ways e.g. by a wedge provided in the shaft 10 or in some other way. Also, they may be connected in the vertical direction of the shaft 10 by various screw fixing means and other similar means. Corre¬ spondingly, the tubes 12a and 12c may be inter- connected in various way, depending on the applica¬ tion. The outer tube 12a and the inner tube 12b may be interlocked immovably with respect to each other by the squeezer 12c at the free end of the outer tube 12a. In such a case, the end of the outer tube 12a will be squeezed smaller than its diameter due to a transverse slit 12d formed in the outer tube 12a and a longitudinal slit starting from the transverse slit and extending through the squeezer 12c also starting from the transverse slit, thus fixing the inner tube 12b in position. Furthermore, when the guide plate is provided with a slot of an appropriate width, rods of different diameters can be used merely by changing the springs 17a to 17c. In this way, it is possible to select the diameter as well as the length of the rods according to the requirements in each particular case.

Claims: Claims : 1. Rod cartridge (1) for a rock drilling equip¬ ment, comprising a rotor with guide plates (15a to 15c) for rods (16); end covers (11, 13) having end surfaces (11a, 13a), the rods (16) being placeable be¬ tween the end covers (11, 13); and rotation means (14) mounted in one end cover (13) for rotating the rotor, c h a r a c t e r i z e d in that one of the end surfaces (13a) is displaceable in the longitudinal direction of the rotor so that the distance of the end surface (13a) from the opposite end surface (11a) is adjustable according to the length of the rod (16) to be used. 2. Rod cartridge according to claim 1, c h a r¬ a c t e r i z e d in that the guide plate (15c) closest to the displaceable end surface (13a) is correspondingly displaceable in the longitudinal direction of the rotor. 3. Rod cartridge according to claim 1 or 2, c h a r a c t e r i z e d in that the displaceable end surface (13a) is integral with said one end cover (13) so that the end surface (13a) and the end cover (13) move simultaneously. 4. Rod cartridge according to claim 3, c h a r¬ a c t e r i z e d in that a support arm (12) formed of an outer tube (12a) and an inner tube (12b) is provided between the end covers (11, 13) of the rod cartridge, the inner tube (12b) being movable with respect to the outer tube (12a) in the longitudinal direction of the rod cartridge, and the tubes being arranged to be locked immovable with respect to each other, and that the rotation means are connected to a rotor shaft (10) by a friction connecting sleeve (18) so that they are detachable from the shaft (10) and lockable for rotating it via the friction connecting sleeve (18). 5. Rod cartridge according to claim 4, c h a r¬ a c t e r i z e d in that the guide plate (15c) closest to the end cover (13) is connected to the rotor shaft (10) by a friction connecting sleeve (19) such that it is detachable from the rotor shaft (10) and lockable immovable with respect to it by means of the friction connecting sleeve (19). 6. Rod cartridge according to claim 1 or 2, c h a r a c t e r i z e d in that the displaceable end surface (13a) forms part of a separate end plate (13b) displaceable in the longitudinal direction of the rotor shaft (10). 7. Rod cartridge according to claim 6, c h a r¬ a c t e r i z e d in that the separate end plate (13b) is mounted for rotation with the rotor shaft (10). 8. Rod cartridge according to claim 7, c h a r- a c t e r i z e d in that the end plate (13b) and the guide plate (15c) close to it are connected to form a single displaceable unit. 9. Rod cartridge according to claim 8, c h a r¬ a c t e r i z e d in that the end plate (13b) and the guide plate (15c) are connected to the rotor shaft (10) by a friction connecting sleeve (19) so that they are together displaceable in the longitudinal direc¬ tion of the rotor shaft (10) when the friction con¬ necting sleeve (19) is opened and correspondingly lockable unrotatable and axially immovable with respect to the shaft (10) by tightening the friction connecting sleeve (19). 10. Rod cartridge according to any of the preceding claims, c h a r a c t e r i z e d in that both of the end surfaces (11a, 13a) form part of separate end plates (lib, 13b) rotating with the rotor shaft (10).

Inventors: LAUNIEMI MARKKU, TIENARI OSSI, LAUNIEMI, MARKKU, TIENARI, OSSI
Applicants: LAUNIEMI MARKKU, TAMROCK OY, TIENARI OSSI, LAUNIEMI, MARKKU, TIENARI, OSSI
Application year: 1994
Main classification: E21B19
IPC codes: E21B19